Methods and apparatus for interconnecting well tool assemblies in continuous tubing strings

ABSTRACT

A well tool assembly interconnection method is provided. In a described embodiment, a continuous tubing string has connectors positioned corresponding to desired locations for tool assemblies in a well. The tubing string is wrapped on a reel and transported to a well. As the tubing string is deployed from the reel into the well, the tool assemblies are interconnected between the connectors. A tool assembly having sensors embedded in a sidewall thereof is also provided.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation of co-pending application Ser.No. 10/396,590 filed Mar. 25, 2003, which is a divisional of applicationSer. No. 09/789,249 filed Feb. 20, 2001, now U.S. Pat. No. 6,561,278 B2.

BACKGROUND

[0002] The present invention relates generally to operations performedand equipment utilized in conjunction with a subterranean well and, inan embodiment described herein, more particularly provides methods andapparatus for interconnecting well tool assemblies in continuous tubingstrings.

[0003] Continuous tubing strings, such as coiled tubing strings, havebeen used for many years in wells. However, one problem with continuoustubing strings is how to interconnect well tool assemblies in the tubingstrings.

[0004] If a well tool assembly is to be interconnected in a continuoustubing string then, of course, the tubing string must be severed andconnections must be made between the tool assembly and the tubing ateach end of the tool assembly. With present methods and apparatus, thisoperation may require many hours to perform.

[0005] Continuous tubing strings having lines embedded in theirsidewalls have recently become available for use in wells. An example isFIBERSPAR composite coiled tubing available from Fiberspar SpoolableProducts, Inc. of Houston, Tex. The FIBERSPAR composite coiled tubing isa composite coiled tubing with eight conductors embedded in itssidewall. Making a connection between this tubing and a tool assembly ata wellsite, where the tubing is severed (i.e., there is no preexistingconnector attached to the tubing), typically takes approximately 12hours to accomplish.

[0006] One solution that has been proposed is to interconnect well toolassemblies in the tubing string, and then spool the well tool assemblieson a reel along with the tubing. The reel is then delivered to thewellsite with the tool assemblies already interconnected therein, andthe tubing string may be conveyed into the well, without having to makeconnections at the wellsite. One problem with this approach is that thewell tool assemblies may have an outer diameter greater than that of thetubing, in which case spooling the tool assemblies on the reel with thetubing may cause damaging stresses to be imparted to the tubing, andspecial injector heads are needed to convey the large diameter toolassemblies into the well. Another problem is that many tool assemblies,such as well screens and packers, may be too long and inflexible to bespooled onto the reel.

[0007] Therefore, it may be seen that there exists a need for improvedmethods and apparatus for interconnecting well tool assemblies incontinuous tubing strings.

SUMMARY

[0008] In carrying out the principles of the present invention, inaccordance with embodiments thereof, methods and apparatus are providedwhich solve the above problems in the art. In one embodiment, a methodis provided which permits well tool assemblies to be rapidlyinterconnected in a continuous tubing string at a wellsite.

[0009] In one aspect of the invention, a method is provided in whichtool connectors are attached to a tubing string at respectivepredetermined downhole locations for tool assemblies. The tubing stringis wrapped onto a reel with the attached connectors. The tubing stringis then deployed into a well from the reel. As the tubing string isdeployed, the tool assemblies are connected to the respectiveconnectors.

[0010] In another aspect of the invention, a method is provided whichpermits a line extending through a tubing string to be extended througha tool assembly interconnected into the tubing string. Connectors areused which both connect the line at each end of the tool assembly andstructurally attach the tool assembly to the tubing. Such connectors arealso used to connect between portions of the tubing.

[0011] In a further aspect of the invention, a connector system isprovided. A connector of the system includes a gripping structure forgrippingly engaging the tubing string, an internal seal structure forsealingly engaging an interior of the tubing string and an external sealstructure for sealingly engaging an exterior of the tubing string. Wherethe tubing string has a line extending therethrough, the connectorincludes a line connector attached to the line in the tubing string.

[0012] In a still further aspect of the invention, a sensor apparatus isprovided. The sensor apparatus includes sensors embedded in a sidewallmaterial of a tubular body of the apparatus. The sensors are connectedto one or more lines also embedded in the sidewall material.

[0013] These and other features, advantages, benefits and objects of thepresent invention will become apparent to one of ordinary skill in theart upon careful consideration of the detailed description ofrepresentative embodiments of the invention hereinbelow and theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a schematic partially cross-sectional side view of anapparatus embodying principles of the present invention;

[0015]FIG. 2 is an elevational view of a tubing reel utilized in theapparatus of FIG. 1;

[0016]FIGS. 3-5 are side elevational views of alternate connectorsystems utilized in the apparatus of FIG. 1;

[0017]FIG. 6 is a quarter-sectional view of a first connector embodyingprinciples of the present invention;

[0018]FIG. 7 is a quarter-sectional view of a second connector embodyingprinciples of the present invention;

[0019]FIG. 8 is an enlarged cross-sectional view of an alternate sealstructure for use with the second connector;

[0020]FIG. 9 is a partially cross-sectional view of a sensor apparatusembodying principles of the present invention; and

[0021]FIG. 10 is a schematic partially cross-sectional side view of avariation of the apparatus of FIG. 1.

DETAILED DESCRIPTION

[0022] Representatively illustrated in FIG. 1 is an apparatus 10 whichembodies principles of the present invention. In the followingdescription of the apparatus 10 and other apparatus and methodsdescribed herein, directional terms, such as “above”, “below”, “upper”,“lower”, etc., are used only for convenience in referring to theaccompanying drawings. Additionally, it is to be understood that thevarious embodiments of the present invention described herein may beutilized in various orientations, such as inclined, inverted,horizontal, vertical, etc., and in various configurations, withoutdeparting from the principles of the present invention.

[0023] In the apparatus 10, a continuous tubing string 12 is deployedinto a well from a reel 14. Since the tubing string 12 is initiallywrapped on the reel 14, such continuous tubing strings are commonlyreferred to as “coiled” tubing strings. As used herein, the term“continuous” means that the tubing string is deployed substantiallycontinuously into a well, allowing for some interruptions tointerconnect tool assemblies therein, as opposed to the manner in whichsegmented tubing is deployed piecemeal into a well in “joints” or in“stands” limited in length by the height of a rig at the well.

[0024] Tubing 16 comprises the vast majority of the tubing string 12.The tubing 16 may be made of a metallic material, such as steel, or itmay be made of a nonmetallic material, such as a composite material. Asdescribed below, the present invention also provides connectors whichpermit tool assemblies to be interconnected in the tubing string 12where the tubing 16 is made of a composite material and has linesembedded in a sidewall thereof.

[0025] In the past, tool assemblies in a continuous tubing string haveeither been spliced into the tubing string just before being deployedinto a well, or have been wrapped on a reel with the tubing, so that nosplicing is needed when the tubing string is deployed into the well. Theformer method is very time-consuming and inconvenient to perform at thewell, especially in those cases where a composite tubing is used, orwhere lines extend through the tubing string. The second method requiresthat the tool assemblies be wrapped on the reel, which may be impossiblefor very long or rigid assemblies, or for assemblies with diameters solarge that they interfere with the wrapping of the tubing on the reel,and which requires special expandable injector heads, as described inU.S. Pat. No. 6,082,454, the disclosure of which is incorporated hereinby this reference.

[0026] In the present apparatus 10, well tool assemblies 18 (a packer),20 (a valve), 22 (a sensor apparatus), 24 (a well screen) and 26 (aspacer or blast joint) are interconnected in the tubing string 12without requiring splicing of the tubing 16 at the well, and withoutrequiring the tool assemblies to be wrapped on the reel 14. Instead,connectors 28, 30 are provided in the tubing string 12 above and below,respectively, each of the tool assemblies 18, 20, 22, 24, 26. Theseconnectors 28, 30 are incorporated into the tubing string 12 prior to,or as, it is being wrapped on the reel 14, with each connector'sposition in the tubing string 12 on the reel 14 corresponding to adesired location for the respective tool assembly in the well.

[0027] That is, the connectors 28, 30 are placed in the tubing string 12at appropriate positions, so that when the tool assemblies 18, 20, 22,24, 26 are interconnected to the connectors 28, 30 and the tubing string12 is deployed into the well, the tool assemblies will be at theirrespective desired locations in the well. The tubing string 12 with theconnectors 28, 30 is wrapped on the reel 14 prior to being transportedto the well. At the well, the tool assemblies 18, 20, 22, 24, 26 areinterconnected between the connectors 28, 30 as the tubing string 12 isdeployed into the well from the reel 14. In this manner, the toolassemblies 18, 20, 22, 24, 26 do not have to be wrapped on the reel 14,and the tool assemblies do not have to be spliced into the tubing 16 atthe well.

[0028] Referring additionally now to FIG. 2, a view of the reel 14 isdepicted in which the connectors 28, 30 are shown wrapped with thetubing 16 on the reel 14. In this view it may be clearly seen that theconnectors 28, 30 are interconnected to the tubing 16 prior to thetubing 16 being wrapped on the reel 14. As described above, theconnectors 28, 30 are positioned to correspond to desired locations ofparticular tool assemblies in a well. Placeholders 38 are used tosubstitute for the respective tool assemblies between the connectors 28,30 when the tubing 16 is wrapped on the reel 14.

[0029] Referring additionally now to FIGS. 3-5, various alternateconnector systems 32, 34, 36 are representatively illustrated. In thesystem 32 depicted in FIG. 3, both of the connectors 28, 30 aremale-threaded, and so a placeholder 40 used to connect the connectors28, 30 together while the tubing string 16 is on the reel 14 hasopposing female threads. In the system 34 depicted in FIG. 4, theconnector 28 has male threads, the connector 30 has female threads, andso a placeholder 42 has both male and female threads. In the system 36depicted in FIG. 5, no placeholder is used. Instead, the male-threadedconnector 28 is directly connected to the female-threaded connector 30when the tubing 16 is wrapped on the reel 14.

[0030] Thus, it may be clearly seen that a variety of methods may beused to provide the connectors 28, 30 in the tubing string 12. Ofcourse, it is not necessary for the connectors 28, 30 to be threaded, orfor any particular type of connector to be used. Any connector may beused in the apparatus 10, without departing from the principles of thepresent invention.

[0031] Referring additionally now to FIG. 6, a connector 44 embodyingprinciples of the present invention is representatively illustrated. Theconnector 44 may be used for the connector 28 or 30 in the apparatus 10,or it may be used in other apparatus.

[0032] The connector 44 is configured for use with a composite tubing46, which has one or more lines 48 embedded in a sidewall thereof. Aslip, ferrule or serrated wedge 50, or multiple ones of these, is usedto grip an exterior surface of the tubing 46. The slip 50 is biased intogripping engagement with the tubing 46 by tightening a sleeve 58 onto ahousing 60.

[0033] A seal 52 seals between the exterior surface of the tubing 46 andthe sleeve 58. Another seal 54 seals between an interior surface of thetubing 46 and the housing 60. A further seal 62 seals between the sleeve58 and the housing 60. In this manner, an end of the tubing 46 extendinginto the connector 44 is isolated from exposure to fluids inside andoutside the connector.

[0034] A barb 56 or other electrically conductive member is insertedinto the end of the tubing 46, so that the barb 56 contacts the line 48.A potting compound 72, such as an epoxy, may be used about the end ofthe tubing 46 and the barb 56 to prevent the barb 56 from dislodgingfrom the tubing 46 and/or to provide additional sealing for theelectrical connection. Another conductor 64 extends from the barb 56through the housing 60 to an electrical contact 66. The barb 56,conductor 64 and contact 66 thus provide a means of transmittingelectrical signals and/or power from the line 48 to the lower end of theconnector 44.

[0035] Shown in dashed lines in FIG. 6 is a mating connector or toolassembly 68, which includes another electrical contact 70 fortransmitting the signals/power from the contact 66 to the connector ortool assembly 68.

[0036] Although the line 48 has been described above as being anelectrical line, it will be readily appreciated that modifications maybe made to the connector 44 to accommodate other types of lines. Forexample, the line 48 could be a fiber optic line, in which case a fiberoptic coupling may be used in place of the contact 66, or the line 48could be a hydraulic line, in which case a hydraulic coupling may beused in place of the contact 66. In addition, the line 48 could be usedfor various purposes, such as communication, chemical injection,electrical or hydraulic power, monitoring of downhole equipment andprocesses, and a control line for, e.g., a safety valve, etc. Of course,any number of lines 48 may be used with the connector 44, withoutdeparting from the principles of the present invention.

[0037] Referring additionally now to FIG. 7, an upper connector 74 and alower connector 76 embodying principles of the present invention arerepresentatively illustrated. These connectors 74, 76 may be used forthe connectors 28, 30 in the apparatus 10, or they may be used in anyother apparatus.

[0038] The connectors 74, 76 are designed for use with a compositetubing 78. The tubing 78 has an outer wear layer 80, a layer 82 in whichone or more lines 84 is embedded, a structural layer 86 and an innerflow tube or seal layer 88. This tubing 78 is similar to the FIBERSPARcomposite coiled tubing referred to above. One or more lines 90 may alsobe embedded in the seal layer 88.

[0039] The wear layer 80 provides abrasion resistance to the tubing 78.The structural layer 86 provides strength to the tubing 78, but thestructural layer 86 may be somewhat porous. The layers 82, 88 isolatethe structural layer 86 from contact with fluids internal and externalto the tubing 78, and provide sealed pathways for the lines 84, 90 in asidewall of the tubing 78. Thus, if the lines 84, 90 are electricalconductors, the layers 82, 88 provide insulation for the lines. Ofcourse, any type of line may be used for the lines 84, 90, withoutdeparting from the principles of the invention.

[0040] The upper connector 74 includes an outer housing 92, a sleeve 94threaded into the housing 92, a mandrel 96 and an inner seal sleeve 98.The upper connector 74 is sealed to an end of the tubing 78 extendinginto the upper connector 74 by means of a seal assembly 100, which iscompressed between the sleeve 94 and the housing 92, and by means ofsealing material 102 carried externally on the inner seal sleeve 98.

[0041] The mandrel 96 grips the structural layer 86 with multiplecollets 104 (only one of which is visible in FIG. 7) having teeth formedon inner surfaces thereof. Multiple inclined surfaces are formedexternally on each of the collets 104, and these inclined surfacescooperate with similar inclined surfaces formed internally on thehousing 92 to bias the collets 104 inward into engagement with thestructural layer 86. A pin 106 prevents relative rotation between themandrel 96 and the tubing 78.

[0042] The line 84 extends outward from the layer 82 and into the upperconnector 74. The line 84 passes between the collets 104 and into apassage 108 formed through the mandrel 96. At a lower end of the mandrel96, the line 84 is connected to a line connector 110. If the line 90 isprovided in the seal layer 88, the line 90 may also extend through thepassage 108 in the mandrel 96 to the line connector 110, or to anotherline connector

[0043] The line connector 110 is depicted as being a pin-type connector,but it may be a contact, such as the contact 66 described above, or itmay be any other type of connector. For example, if the lines 84, 90 arefiber optic or hydraulic lines, then the line connector 110 may be afiber optic or hydraulic coupling, respectively.

[0044] When the connectors 74, 76 are connected to each other, anannular projection 112 formed on a lower end of the inner seal sleeve 98initially sealingly engages an annular seal 114 carried on an upper endof an inner sleeve 116 of the lower connector 76. Further tightening ofa threaded collar 118 between the housing 92 and a housing 120 of thelower connector 76 eventually brings the line connector 110 intooperative engagement with a mating line connector 122 (depicted in FIG.7 as a socket-type connector) in the lower connector 76, and then bringsan annular projection 124 into sealing engagement with an annular seal126 carried on an upper end of the housing 120. The seals 114, 126isolate the line connectors 110, 122 (and the interiors of theconnectors 74, 76) from fluid internal and external to the connectors

[0045] Since the lower connector 76 is otherwise similarly configured tothe upper connector 74, it will not be further described herein. Notethat both of the connectors 74, 76 may be connected to tool assemblies,such as the tool assemblies 18, 20, 22, 24, 26, so that connections tolines may be made on either side of each of the tool assemblies. Thus,the lines 84, 90 may extend through each of the tool assemblies from aconnector above the tool assembly to a connector below the toolassembly. This functionality is also provided by the connector 44described above

[0046] Referring additionally now to FIG. 8, an alternate sealconfiguration 128 is representatively illustrated. The sealconfiguration 128 may be used in place of either the projection 112 andseal 114, or the projection 124 and seal 126, of the connectors 74, 76.

[0047] The seal configuration 128 includes an annular projection 130 andan annular seal 132. However, the projection 130 and seal 132 areconfigured so that the projection 130 contacts shoulders 134, 136 toeither side of the seal 132. This contact prevents extrusion of the seal132 due to pressure, and also provides metal-to-metal seals between theprojection 130 and the shoulders 134, 136.

[0048] Referring additionally now to FIG. 9, an example isrepresentatively illustrated of a tool assembly 138 which may beinterconnected in a continuous tubing string. The tool assembly 138 is asensor apparatus. It includes sensors 140, 142, 144, 146 interconnectedto lines 148, 150 embedded in a sidewall material of a tubular body 152of the tool assembly 138

[0049] The sensors 140, 142, 144, 146 are also embedded in the sidewallmaterial of the body 152. The sensors 140, 142, 144 sense parametersinternal to the body 152, and the sensor 146 senses one or moreparameter external to the body 152. Any type of sensor may be used forany of the sensors 140, 142, 144, 146

[0050]

[0051] For example, pressure and temperature sensors may be used. Itwould be particularly advantageous to use a combination of types ofsensors for the sensors 140, 142, 144, 146 which would allow computationof values, such as multiple phase flow rates through the tool assembly138

[0052] As another example, it would be advantageous to use a seismicsensor for one or more of the sensors 140, 142, 144, 146. This wouldmake available seismic information previously unobtainable from theinterior of a sidewall of a tubing string.

[0053] Note that the sidewall material is preferably a nonmetalliccomposite material, but other types of materials may be utilized, inkeeping with the principles of the invention. In particular, the body152 could be a section of composite tubing, in which the sensors 140,142, 144, 146 have been installed and connected to the lines 148,150.

[0054] The lines 148, 150 may be any type of line, including electrical,hydraulic, fiber optic, etc. Additional lines (not shown in FIG. 9) mayextend through or into the tool assembly 138. Connectors 154, 156 permitthe tool assembly 138 to be conveniently interconnected in a tubingstring. For example, the connector 76 described above may be used forthe connector 154, and the connector 74 described above may be used forthe connector 156. Via the connectors 154, 156, the lines 148, 150 areconnected to lines extending through tubing or other tool assembliesattached to each end of the tool assembly 138

[0055] Referring additionally now to FIG. 10, the apparatus 10 isrepresentatively illustrated wherein a tool assembly 160 is beinginterconnected into the tubing string 12. The tool assembly 160 is toolong, too rigid, or too large in diameter to be wrapped on the reel 14with the tubing 16.

[0056] Connectors 28, 30 are separated (and a placeholder 38 is removed,if necessary) prior to interconnecting the tool assembly 160 in thetubing string 12. The tool assembly 160 is connected to the lowerconnector 30, the tubing string 12 is lowered, and then the toolassembly 160 is connected to the upper connector 28. As described above,the connectors 28, 30 are provided already connected to the tubing 16when the tubing 16 is wrapped on the reel 14 and transported to thewell, so that when the tool assembly 160 is interconnected between theconnectors 28, 30 and the tubing string 12 is deployed into the well,the tool assembly 160 will be appropriately positioned in the well.

[0057] In one embodiment of the present invention, the tool assembly 160is a spacer used to space out other equipment in the tubing string 12.An example of this use is shown in FIG. 1, wherein the tool assembly 26may be used to correct or adjust the spacing between, e.g., the wellscreen 24 and perforations in the well. Such corrections or adjustmentsin tool spacings in the tubing string 12 are conveniently made at thewellsite by means of the tool assembly 160 or 26. Note that, when usedin this manner, the tool assembly 160 or 26 is not necessarily too long,too rigid, or too large in diameter to be wrapped on the reel 14 withthe tubing 16.

[0058] Of course, a person skilled in the art would, upon a carefulconsideration of the above description of representative embodiments ofthe invention, readily appreciate that many modifications, additions,substitutions, deletions, and other changes may be made to thesespecific embodiments, and such changes are contemplated by theprinciples of the present invention. Accordingly, the foregoing detaileddescription is to be clearly understood as being given by way ofillustration and example only, the spirit and scope of the presentinvention being limited solely by the appended claims.

What is claimed is:
 1. A sensor apparatus for interconnection in atubular string in a well, comprising: a generally tubular body having asidewall material; at least one line embedded in the sidewall material;and at least one sensor embedded in the sidewall material andoperatively connected to the line.
 2. The sensor apparatus according toclaim 1 wherein the sidewall material is nonmetallic.
 3. The sensorapparatus according to claim 1 wherein the sidewall material is acomposite material.
 4. The sensor apparatus according to claim 1 whereinthe line is a selected one of a hydraulic line, an electrical line and afiber optic line.
 5. The sensor apparatus according to claim 1 whereinthe line is a selected one of a communication line, a power line, acontrol line and a monitoring line.
 6. The sensor apparatus according toclaim 1 wherein the sensor senses a parameter internal to the tubularbody.
 7. The sensor apparatus according to claim 1 wherein the sensorsenses a parameter external to the tubular body.
 8. The sensor apparatusaccording to claim 1 wherein the sensor is a seismic sensor.